Xinjing coal mine, near the city of
Qingtongxia in Ningxia Province.
Unlike the neighbouring
Shanxxi Province, Ningxia is not
necessarily known for providing
high yields of raw materials. The
region is perhaps better known for
holding a number of Chinese
artefacts from the Tang Dynasty
under its desert surface. In fact, little
is known about the ecosystem of the
region, as it is one the least studied
in the world. However, the Xinjing
mine has a production yield of
around 2 million tpa of coal – no
small amount for a mine that sits
within sight of the renowned
Gobi Desert.
High yields may make attractive
numbers to reel off, but they are moot
without a robust transport solution,
which can go beyond mere logistics.
The fleet captain at Xinjing Coal Ltd
understands this, which is why a fleet
of GL8606K420CA6K Xi Bei Lang
dump trucks have been tasked with
transporting coal within the borders of
the Xinjing mine.
These trucks have to make 5 km
up to 40 times a day, when laden
with some 30 t of coal cinders. In
doing so, they must travel across
steep rutted slopes that are
smothered with billowing clouds of
sand and displaced road dust.
Because of this, they must be
equipped with tough powertrain
components. Otherwise, the
year‑round daily marathon would
quickly take its toll and the
subsequent maintenance downtime
would significantly erode the Xinjing
mine’s annual coal production and
fleet productivity.
To deal with such a margin-eating
problem, the 10 Xi Bei Lang dumpers
feature powertrains fitted with a
Cummins ISME420 30 engine and an
Allison 4500ORS fully-automatic
transmission.
The use of components made by
international, rather than domestic
Chinese Tier One manufacturers, is
twofold: firstly, the Xi Bei Lang
dumpers match the standards of
similar trucks from other Chinese
OEMs, such as NHL and Yutong.
Secondly, these components have a
global reputation for delivering the
performance critical for ensuring a
mining operation is successful. Where
once minimum specification vehicles
were standard, the massive growth of
Chinese heavy industry has increased
demands for off‑highway vehicles
that are equipped with high-quality
components.
To truly understand why this is
becoming the norm and how a
high-quality powertrain can
safeguard profitable mining
operations, one needs to take a closer
look at the specification of the
Xi Bei Lang dumper trucks and their
duty-cycles at the Xinjing mine.
Powertrains: the specs
The engines found in the trucks come
from the Cummins ISME series,
which features engines designed to
deliver high levels of torques at low
RPM to provide pulling power
without excessive fuel consumption.
Furthermore, the engines are fitted
with the manufacturer’s proprietary
INTERACT System, which provides
continuous feedback from
engine‑mounted sensors that monitor
all of its critical parameters. This
means that, in the case of a
malfunction, the system
automatically de-rates the engine
torque and speed until the problem is
solved. This helps avoid powertrain
damage – and thus vehicle
downtime.
The Allison 4500ORS,
fully‑automatic transmission has
been added to the mix in order to
enhance truck operation and
powertrain performance.
A dangerous manoeuvre
There is one particular task in the
duty-cycle of Xinjing Mine’s
trucks that demonstrates
Allison’s experience and the
many advantages of specifying a
fully-automatic transmission over a
manual counterpart.
The Xi Bei Lang dumpers are
often required to take their 30 t coal
payload and tip from a rugged
drop-off point – a near 90˚ cliff.
Even for experienced drivers, this is
a perilous task. An incorrect
manoeuvre, no matter how minor,
could place both the truck and its
driver into a potentially dangerous
situation.
The 4500ORS transmission helps
to improve performance and
alleviate the risk involved with such
a manoeuvre in several ways.
Firstly, the driver is not required to
concentrate on selecting an
September 2014
|
World Coal
|
35
Typically, each GL8606K420CA6K Xi Bei Lang mining dump truck makes 5 km trips 40
times a day, over inclines of more than 200 m, while carrying 30 t.
